U.S. patent number 11,289,038 [Application Number 16/836,134] was granted by the patent office on 2022-03-29 for pixel charging method for adjusting sub-pixel charging time, pixel charging circuit, display device and display control method.
This patent grant is currently assigned to Beijing BOE Display Technology Co., Ltd., BOE TECHNOLOGY GROUP CO., LTD.. The grantee listed for this patent is Beijing BOE Display Technology Co., Ltd., BOE TECHNOLOGY GROUP CO., LTD.. Invention is credited to Jianhua Huang, Jian Li, Senwang Li, Guohuo Su, Zhihua Sun, Hui Zhang, Yinshu Zhang.
United States Patent |
11,289,038 |
Sun , et al. |
March 29, 2022 |
Pixel charging method for adjusting sub-pixel charging time, pixel
charging circuit, display device and display control method
Abstract
The present disclosure relates to the field of display
technology and, in particular, to a pixel charging method, a pixel
charging circuit, a display device, and a display control method.
The pixel charging method includes acquiring a state of a backlight
source and adjusting a charging time of a sub-pixel corresponding
to the backlight source according to the state of the backlight
source. When the backlight source is in an on state, the charging
time of the sub-pixel corresponding to the backlight source is a
first charging time. When the backlight source is in an off state,
the charging time of the sub-pixel corresponding to the backlight
source is a second charging time, the second charging time being
shorter than the first charging time.
Inventors: |
Sun; Zhihua (Beijing,
CN), Zhang; Yinshu (Beijing, CN), Li;
Jian (Beijing, CN), Li; Senwang (Beijing,
CN), Su; Guohuo (Beijing, CN), Huang;
Jianhua (Beijing, CN), Zhang; Hui (Beijing,
CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Beijing BOE Display Technology Co., Ltd.
BOE TECHNOLOGY GROUP CO., LTD. |
Beijing
Beijing |
N/A
N/A |
CN
CN |
|
|
Assignee: |
Beijing BOE Display Technology Co.,
Ltd. (Beijing, CN)
BOE TECHNOLOGY GROUP CO., LTD. (Beijing, CN)
|
Family
ID: |
68974853 |
Appl.
No.: |
16/836,134 |
Filed: |
March 31, 2020 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20210097946 A1 |
Apr 1, 2021 |
|
Foreign Application Priority Data
|
|
|
|
|
Sep 30, 2019 [CN] |
|
|
201910940071.2 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09G
3/3607 (20130101); G09G 2310/0251 (20130101); G09G
3/3648 (20130101); G09G 3/3406 (20130101); G09G
3/3611 (20130101); G09G 2320/0626 (20130101); G09G
2320/0633 (20130101); G09G 2320/0646 (20130101); G09G
2320/064 (20130101) |
Current International
Class: |
G09G
5/00 (20060101); G09G 3/36 (20060101); G09G
3/34 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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101393727 |
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Mar 2009 |
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CN |
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101398553 |
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Apr 2009 |
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CN |
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105355182 |
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Feb 2016 |
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CN |
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106297712 |
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Jan 2017 |
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CN |
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107424572 |
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Dec 2017 |
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CN |
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108648706 |
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Oct 2018 |
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CN |
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112150974 |
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Dec 2020 |
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CN |
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200620194 |
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Jun 2006 |
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TW |
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Other References
First Office Action for CN Patent Application No. 201910940071.2
dated Jan. 25, 2021. cited by applicant.
|
Primary Examiner: Snyder; Adam J
Attorney, Agent or Firm: Thomas | Horstemeyer, LLP
Claims
What is claimed is:
1. A pixel charging method, comprising: acquiring a state of a
backlight source; and adjusting a charging time of a sub-pixel
corresponding to the backlight source according to the state of the
backlight source, wherein: when the state of the backlight source
is an on state, the charging time of the sub-pixel corresponding to
the backlight source is a first charging time; when the state of
the backlight source is an off state, the charging time of the
sub-pixel corresponding to the backlight source is a second
charging time, the second charging time is shorter than the first
charging time, so that when a frame is displayed, a charging rate
of the sub-pixel when the state of the backlight source is the on
state is substantially same as that of the sub-pixel when the state
of the backlight source is the off state, the charging time of the
sub-pixel is a difference between a duration of a gate drive signal
corresponding to the sub-pixel and a gate output enable (GOE) time
corresponding to the sub-pixel, and the GOE time is a time taken
for the gate drive signal to shift from a high-level to a low-level
or a time taken for the gate drive signal to shift from the
low-level to the high-level.
2. The pixel charging method according to claim 1, wherein
acquiring the state of the backlight source comprises: acquiring a
pulse width modulation signal, the pulse width modulation signal
being configured to control the state of the backlight source; and
determining the state of the backlight source based on the pulse
width modulation signal.
3. The pixel charging method according to claim 2, wherein
determining the state of the backlight source based on the pulse
width modulation signal comprises: determining that the state of
the backlight source is the on state when the pulse width
modulation signal is a high-level signal; and determining that the
state of the backlight source is the off state when the pulse width
modulation signal is a low-level signal.
4. The pixel charging method according to claim 1, wherein
acquiring the state of the backlight source comprises: detecting a
brightness of the backlight source; determining that the state of
the backlight source is the on state when the brightness of the
backlight source is greater than a threshold; and determining that
the state of the backlight source is the off state when the
brightness of the backlight source is less than or equal to the
threshold.
5. The pixel charging method according to claim 1, wherein
adjusting the charging time of the sub-pixel corresponding to the
backlight source according to the state of the backlight source
comprises: adjusting the gate output enable time corresponding to
the sub-pixel corresponding to the backlight source according to
the state of the backlight source; and calculating the charging
time corresponding to the gate output enable time based on a
correspondence between the gate output enable time and the charging
time, wherein: when the state of the backlight source is the on
state, the gate output enable time corresponding to the sub-pixel
corresponding to the backlight source is a first gate output enable
time; and when the state of the backlight source is the off state,
the gate output enable time corresponding to the sub-pixel
corresponding to the backlight source is a second gate output
enable time, and the second gate output enable time is greater than
the first gate output enable time.
6. A pixel charging circuit, comprising: a signal acquiring circuit
configured to acquire a state of a backlight source; and an
adjusting circuit coupled to the signal acquiring circuit and
configured to adjust a charging time of a sub-pixel corresponding
to the backlight source according to the state of the backlight
source, wherein: the adjusting circuit is configured to adjust the
charging time of the sub-pixel corresponding to the backlight
source to be a first charging time when the state of the backlight
source is an on state; and the adjusting circuit is configured to
adjust the charging time of the sub-pixel corresponding to the
backlight source to be a second charging time when the state of the
backlight source is an off state, the second charging time is
shorter than the first charging time, so that when a frame is
displayed, a charging rate of the sub-pixel when the state of the
backlight source is the on state is substantially same as that of
the sub-pixel when the state of the backlight source is the off
state, the charging time of the sub-pixel is a difference between a
duration of a gate drive signal corresponding to the sub-pixel and
a gate output enable (GOE) time corresponding to the sub-pixel, and
the GOE time is a time taken for the gate drive signal to shift
from a high-level to a low-level or a time taken for the gate drive
signal to shift from the low-level to the high-level.
7. The pixel charging circuit according to claim 6, wherein the
signal acquiring circuit comprises: a signal acquiring sub-circuit
coupled to a pulse width modulation circuit and configured to
acquire a pulse width modulation signal generated by the pulse
width modulation circuit, wherein the pulse width modulation signal
is configured to control the state of the backlight source; and a
first determining sub-circuit coupled to the signal acquiring
sub-circuit and the adjusting circuit, and configured to determine
the state of the backlight source based on the pulse width
modulation signal and transmit the state of the backlight source to
the adjusting circuit.
8. The pixel charging circuit according to claim 7, wherein the
first determining sub-circuit is configured to determine that the
state of the backlight source is the on state when the pulse width
modulation signal is a high-level signal, and determine that the
state of the backlight source is the off state when the pulse width
modulation signal is a low-level signal.
9. The pixel charging circuit according to claim 6, wherein the
signal acquiring circuit comprises: a brightness detecting
sub-circuit configured to detect brightness of the backlight
source; and a second determining sub-circuit configured to
determine that the state of the backlight source is the on state
when the brightness of the backlight source is greater than a
threshold, and determine that the state of the backlight source is
the off state when the brightness of the backlight source is less
than or equal to the threshold.
10. The pixel charging circuit according to claim 6, wherein the
adjusting circuit comprises: an adjusting sub-circuit, coupled to
the signal acquiring circuit and configured to adjust the gate
output enable time corresponding to the sub-pixel corresponding to
the backlight source according to the state of the backlight
source; and a calculating sub-circuit, coupled to the adjusting
sub-circuit and configured to calculate the charging time
corresponding to the gate output enable time based on a
correspondence between the gate output enable time and the charging
time, wherein: the adjusting sub-circuit is configured to adjust
the gate output enable time corresponding to the sub-pixel
corresponding to the backlight source to be a first gate output
enable time when the state of the backlight source is the on state;
and the adjusting sub-circuit is configured to adjust the gate
output enable time corresponding to the sub-pixel corresponding to
the backlight source to be a second gate output enable time when
the state of the backlight source is the off state, and the second
gate output enable time is longer than the first gate output enable
time.
11. A display device, comprising: a display area and a non-display
area, wherein: the display area comprises a plurality of sub-pixels
arranged in an array; and the non-display area comprises the pixel
charging circuit according to claim 6, and the pixel charging
circuit is coupled to the sub-pixel.
12. The display device according to claim 11, wherein the signal
acquiring circuit comprises: a signal acquiring sub-circuit coupled
to a pulse width modulation circuit and configured to acquire a
pulse width modulation signal generated by the pulse width
modulation circuit, wherein the pulse width modulation signal is
configured to control the state of the backlight source; and a
first determining sub-circuit coupled to the signal acquiring
sub-circuit and the adjusting circuit, and configured to determine
the state of the backlight source based on the pulse width
modulation signal and transmit the state of the backlight source to
the adjusting circuit.
13. The display device according to claim 12, wherein the first
determining sub-circuit is configured to determine that the state
of the backlight source is the on state when the pulse width
modulation signal is a high-level signal, and determine that the
state of the backlight source is the off state when the pulse width
modulation signal is a low-level signal.
14. The display device according to claim 11, wherein the signal
acquiring circuit comprises: a brightness detecting sub-circuit
configured to detect brightness of the backlight source; and a
second determining sub-circuit configured to determine that the
state of the backlight source is the on state when the brightness
of the backlight source is greater than a threshold, and determine
that the state of the backlight source is the off state when the
brightness of the backlight source is less than or equal to the
threshold.
15. The display device according to claim 11, wherein the adjusting
circuit comprises: an adjusting sub-circuit coupled to the signal
acquiring circuit and configured to adjust the gate output enable
time corresponding to the sub-pixel corresponding to the backlight
source according to the state of the backlight source; and a
calculating sub-circuit coupled to the adjusting sub-circuit and
configured to calculate the charging time corresponding to the gate
output enable time based on a correspondence between the gate
output enable time and the charging time, wherein: the adjusting
sub-circuit is configured to adjust the gate output enable time
corresponding to the sub-pixel corresponding to the backlight
source to be a first gate output enable time when the state of the
backlight source is the on state; and the adjusting sub-circuit is
configured to adjust the gate output enable time corresponding to
the sub-pixel corresponding to the backlight source to be a second
gate output enable time when the state of the backlight source is
the off state, and the second gate output enable time is longer
than the first gate output enable time.
16. A display control method applied to a display device,
comprising: providing the display device, wherein the display
device comprises a plurality of pixel display areas, each of the
pixel display areas comprising at least one row of sub-pixels;
acquiring a state of a backlight source corresponding to each of
the pixel display areas; and adjusting a charging time of a
sub-pixel corresponding to the backlight source according to the
state of the backlight source, wherein: when the state of the
backlight source is an on state, the charging time of the sub-pixel
corresponding to the backlight source is a first charging time; and
when the state of the backlight source is an off state, the
charging time of the sub-pixel corresponding to the backlight
source is a second charging time, the second charging time is
shorter than the first charging time, so that when a frame is
displayed, a charging rate of the sub-pixel when the state of the
backlight source is the on state is substantially same as that of
the sub-pixel when the state of the backlight source is the off
state, the charging time of the sub-pixel is a difference between a
duration of a gate drive signal corresponding to the sub-pixel and
a gate output enable (GOE) time corresponding to the sub-pixel, and
the GOE time is a time taken for the gate drive signal to shift
from a high-level to a low-level or a time taken for the gate drive
signal to shift from the low-level to the high-level.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application is based upon and claims priority to Chinese
Patent Application No. 201910940071.2, filed on Sep. 30, 2019, the
entire contents thereof being incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to the field of display technology
and, in particular, to a pixel charging method, a pixel charging
circuit, a display device, and a display control method.
BACKGROUND
A liquid crystal display (LCD) product has many advantages, such as
a thin body, power saving features, no radiation, etc., and has
been widely used in various products, such as LCD TVs, mobile
phones, personal digital assistants (PDAs), digital cameras,
computer screens or laptop screens, etc.
However, current liquid crystal display panels are prone to exhibit
bright and dark stripes when displaying frames, which results in
poor frame uniformity especially when displaying a static
solid-color frame.
It should be noted that the information disclosed in the background
section above is only used to enhance the understanding of the
background of the present disclosure, and therefore, may include
information that does not constitute the prior art known to those
skilled in the art.
SUMMARY
The present disclosure provides a pixel charging method, a pixel
charging circuit, a display device, and a display control
method.
According to a first aspect of the present disclosure, a pixel
charging method is provided, including: acquiring a state of a
backlight source; and adjusting a charging time of a sub-pixel
corresponding to the backlight source according to the state of the
backlight source. When the backlight source is in an on state, the
charging time of the sub-pixel corresponding to the backlight
source is a first charging time; and when the backlight source is
in an off state, the charging time of the sub-pixel corresponding
to the backlight source is a second charging time, where the second
charging time is shorter than the first charging time.
In an exemplary embodiment, the acquiring of a state of a backlight
source includes: acquiring a pulse width modulation signal, the
pulse width modulation signal being configured to control the state
of the backlight source; and determining the state of the backlight
source based on the pulse width modulation signal.
In an exemplary embodiment, the determining the state of the
backlight source based on the pulse width modulation signal
includes: determining that the backlight source is in the on state
when the pulse width modulation signal is a high-level signal; and
determining that the backlight source is in the off state when the
pulse width modulation signal is a low-level signal.
In an exemplary embodiment, the acquiring a state of a backlight
source includes: detecting brightness of the backlight source;
determining that the backlight source is in the on state when the
brightness of the backlight source is greater than a preset
threshold; and determining that the backlight source is in the off
state when the brightness of the backlight source is less than or
equal to the preset threshold.
In an exemplary embodiment, the adjusting a charging time of a
sub-pixel corresponding to the backlight source according to the
state of the backlight source includes: adjusting a gate output
enable time corresponding to the sub-pixel corresponding to the
backlight source according to the state of the backlight source;
and calculating the charging time corresponding to the gate output
enable time based on a preset correspondence between the gate
output enable time and the charging time. When the backlight source
is in the on state, the gate output enable time corresponding to
the sub-pixel corresponding to the backlight source is a first gate
output enable time; and when the backlight source is in the off
state, the gate output enable time corresponding to the sub-pixel
corresponding to the backlight source is a second gate output
enable time, and the second gate output enable time is greater than
the first gate output enable time.
According to a second aspect of the present disclosure, there is
provided a pixel charging circuit, including: a signal acquiring
circuit, configured to acquire a state of a backlight source; and
an adjusting circuit, coupled to the signal acquiring circuit and
configured to adjust a charging time of a sub-pixel corresponding
to the backlight source according to the state of the backlight
source. The adjusting circuit is configured to adjust the charging
time of the sub-pixel corresponding to the backlight source to be a
first charging time when the backlight source is in an on state;
and the adjusting circuit is configured to adjust the charging time
of the sub-pixel corresponding to the backlight source to be a
second charging time when the backlight source is in an off state,
and the second charging time is shorter than the first charging
time.
In an exemplary embodiment, wherein the signal acquiring circuit
includes: a signal acquiring sub-circuit, coupled to a pulse width
modulation circuit and configured to acquire a pulse width
modulation signal generated by the pulse width modulation circuit,
wherein the pulse width modulation signal is configured to control
the state of the backlight source; and a first determining
sub-circuit, coupled to the signal acquiring sub-circuit and the
adjusting circuit, and configured to determine the state of the
backlight source based on the pulse width modulation signal and
transmit the state of the backlight source to the adjusting
circuit.
In an exemplary embodiment, the first determining sub-circuit is
configured to determine that the backlight source is in the on
state when the pulse width modulation signal is a high-level
signal, and determine that the backlight source is in the off state
when the pulse width modulation signal is a low-level signal.
In an exemplary embodiment, the signal acquiring circuit includes:
a brightness detecting sub-circuit, configured to detect brightness
of the backlight source; and a second determining sub-circuit,
configured to determine that the backlight source is in the on
state when the brightness of the backlight source is greater than a
preset threshold, and determine that the backlight source is in the
off state when the brightness of the backlight source is less than
or equal to the preset threshold.
In an exemplary embodiment, wherein the adjusting circuit includes:
an adjusting sub-circuit, coupled to the signal acquiring circuit
and configured to adjust a gate output enable time corresponding to
the sub-pixel corresponding to the backlight source according to
the state of the backlight source; and a calculating sub-circuit,
coupled to the adjusting sub-circuit and configured to calculate
the charging time corresponding to the gate output enable time
based on a preset correspondence between the gate output enable
time and the charging time. The adjusting sub-circuit is configured
to adjust the gate output enable time corresponding to the
sub-pixel corresponding to the backlight source to be a first gate
output enable time when the backlight source is in the on state;
and the adjusting sub-circuit is configured to adjust the gate
output enable time corresponding to the sub-pixel corresponding to
the backlight source to be a second gate output enable time when
the backlight source is in the off state, and the second gate
output enable time is longer than the first gate output enable
time.
According to a third aspect of the present disclosure, there is
provided a display device, including a display area and a
non-display area, the display area includes a plurality of
sub-pixels arranged in an array; and the non-display area includes
anyone of the pixel charging circuits, and the pixel charging
circuit is coupled to the sub-pixel.
According to a fourth aspect of the present disclosure, there is
provided a display control method, applied to a display device. The
display device includes a plurality of pixel display areas, each of
the pixel display areas includes at least one row of sub-pixels,
and the display control method includes: acquiring a state of a
backlight source corresponding to each of the pixel display areas;
and adjusting a charging time of a sub-pixel corresponding to the
backlight source according to the state of the backlight source.
When the backlight source is in an on state, the charging time of
the sub-pixel corresponding to the backlight source is a first
charging time; and when the backlight source is in an off state,
the charging time of the sub-pixel corresponding to the backlight
source is a second charging time, and the second charging time is
shorter than the first charging time.
It should be understood that the above general description and the
following detailed description are merely exemplary and
explanatory, and should not limit the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings herein are incorporated in and constitute a part of
the specification, illustrate embodiments consistent with the
present disclosure, and together with the description serve to
explain the principles of the present disclosure. Understandably,
the drawings in the following description are just some embodiments
of the present disclosure. For those of ordinary skill in the art,
other drawings can be obtained according to these drawings without
creative efforts.
FIG. 1 is a schematic diagram showing a correspondence among a
state of a backlight source, a pixel charging rate, and a
bright-dark state of a sub-pixel within one frame time in the
related art;
FIG. 2 shows a flowchart of a pixel charging method according to an
embodiment of the present disclosure;
FIG. 3 is a block diagram of a pixel charging circuit according to
an embodiment of the present disclosure;
FIG. 4 is a schematic diagram illustrating a connection between a
timing controller and a driver for driving a backlight source
according to an embodiment of the present disclosure; and
FIG. 5 is a schematic diagram illustrating a correspondence among a
state of a backlight source, a GOE time length, a pixel charging
rate, and a bright-dark state of a sub-pixel within one frame time
according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
Example embodiments will now be described more fully with reference
to the accompanying drawings. However, the example embodiments may
be implemented in various forms and should not be construed as
being limited to the embodiments set forth herein. Rather, these
embodiments are provided so that the present disclosure will be
comprehensive and complete, and will fully convey the concepts of
the example embodiments to those skilled in the art. The same
reference numerals in the drawings denote the same or similar
structures, and thus their detailed descriptions will be
omitted.
Although relative terms, such as "on" and "under," are used in this
specification to describe a relative relationship between one
component and another component shown in the drawings, these terms
are used in this specification for convenience only, for example,
according to the direction of the examples described in the
drawings. It can be understood that if the device shown in the
drawings is turned upside down, the component described "on" will
become the component "below." When a structure is "on" another
structure, it may mean that the structure is integrally formed on
the another structure, or that the structure is "directly" provided
on the another structure, or that the structure is "indirectly"
provided on the another structure through an other structure.
Compared with a cold cathode fluorescent lamp (CCFL) light source,
a light emitting diode (LED) light source has advantages such as
low power consumption, long life and high brightness, and thus,
more and more liquid crystal displays devices (especially
large-size liquid crystal display devices) started using the LED
light sources as backlight sources. At the same time, in order to
further improve a contrast of and thus a display quality of a
liquid crystal display frame, the LED light source, when being used
as the backlight source of the liquid crystal display device, can
be adjusted by a backlight source adjusting technology.
LED backlight adjusting technologies currently used include an LED
analog backlight-adjusting technology and a pulse width modulation
(PWM) backlight-adjusting technology. However, when the LED analog
backlight-adjusting technology is used to adjust the LED light
source, it is usually implemented by directly changing current
flowing through the LED, which will seriously affect luminous
quality of the LED. Moreover, the use of analog backlight-adjusting
technology will often increase energy consumption of an entire
system. Therefore, the PWM backlight-adjusting technology is mostly
used in the LED backlight source driving of the liquid crystal
display device (especially the large-size liquid crystal display
device).
The PWM backlight-adjusting technology is a backlight-adjusting
technology that uses a simple pulse signal to repeatedly turn on
and off an LED driver. The PWM backlight-adjusting technology
controls brightness of a backlight LED by adjusting a frequency and
a duty cycle of the pulse signal. A modulation frequency of a PWM
signal may be an integer multiple of a matched frame frequency of a
display panel, and the display panel can be scanned row by row.
Since the display panel is scanned row by row, when one frame is
displayed, a part of the sub-pixels on the display panel are
scanned while the backlight source is in an on state, and the other
part of the sub-pixels are scanned while the backlight source is in
an off state. For example, as shown in FIG. 1, within one frame
time, the backlight has 3 changing-cycles, and 2160 rows of
sub-pixels (excluding blanking areas) of the display panel are
scanned. According to the backlight cycle, the 2160 rows of
sub-pixels can be divided into 6 pixel display areas, that is, each
of pixel display area includes 360 rows of sub-pixels and
corresponds to a periodic on or off state of the backlight
source.
It should be noted that when the backlight source is in the off
state (corresponding to OFF in FIG. 1), an active layer (made of
semiconductor material) in a corresponding pixel circuit to the
backlight source can be understood as an insulating layer, and in
this case, a dielectric constant thereof may be .sub.1. When the
backlight source is in the on state (corresponding to ON in FIG.
1), the active layer (made of the semiconductor material) in the
corresponding pixel circuit to the backlight source will become an
electrical conductor under light irradiation, and in this case, the
dielectric constant thereof may be .sub.2, where .sub.2 is greater
than .sub.1. Based on the capacitance calculation formula C= S/d,
it can be seen that when a distance d and an opposite area S
between the active layer and a gate is constant, the larger the
dielectric constant , the larger the capacitance C generated
between the active layer and the gate is. The larger the
capacitance C, the more serious the time delay is, which will
reduce a pixel charging rate so that the brightness of a
corresponding pixel is relatively lower.
That is, as shown in FIG. 1, the charging rate of the sub-pixel
scanned when the backlight source is in the on state is lower than
that of the sub-pixel scanned when the backlight source is in the
off state. Therefore, bright and dark stripes are exhibited due to
different charging rates when a frame is displayed, and the
uniformity of the frame is not good, especially when a static
solid-color frame is displayed.
In order to solve the above problem, the inventors proposes a
solution, in which a modulation frequency of a backlight source is
increased, that is, to 15 KHz. When the modulation frequency of the
backlight source is increased to 15 KHz, human eyes can't
distinguish the bright and dark stripes. However, since the
frequency is too large, the service life of an LED will be greatly
reduced, and thus this solution does not fundamentally solve this
problem.
Based on the foregoing, the inventors provide another solution, and
specifically provides a pixel charging method.
As shown in FIG. 2, the pixel charging method includes: step S10,
acquiring a state of a backlight source; and step S20, adjusting a
charging time of a sub-pixel corresponding to the backlight source
according to the state of the backlight source. When the backlight
source is in an on state, the charging time of the sub-pixel
corresponding to the backlight source is a first charging time; and
when the backlight source is in an off state, the charging time of
the sub-pixel corresponding to the backlight source is a second
charging time, and the second charging time is shorter than the
first charging time.
In this embodiment, the state of the backlight source is acquired,
and the charging time of the sub-pixel corresponding to the
backlight source is adjusted according to the state of the
backlight source. Specifically, the charging time of the sub-pixel
corresponding to the backlight source when the backlight source is
in the on state shall be longer than the charging time of the
sub-pixel corresponding to the backlight source when the backlight
source is in the off state, which can increase the charging rate of
the sub-pixel when the backlight source is in the on state, so that
the charging rates of the sub-pixels are substantially the same
when corresponding backlight sources are in different states.
Therefore, it can ensure that display brightness of the sub-pixels
is subtantially uniform when the corresponding backlight sources
are in the different states, and then it can prevent a single
sub-pixel from flickering when the state of the backlight source is
changed. In addition, when a frame is displayed, charging effects
of the sub-pixel corresponding to the different states of the
backlight source is substantially the same, that is, the brightness
thereof is substantially the same, which can prevent bright and
dark stripes from exhibiting on one frame, and then can ensure the
uniformity of the frame, thereby improve the display effect.
It should be understood that the backlight source of this
embodiment may be an LED backlight source.
As described above, the state of the backlight source may be
adjusted by the PWM backlight-adjusting technology. Therefore, in
an embodiment, the acquiring a state of a backlight source may
specifically include: step S102, acquiring a pulse width modulation
signal (i.e., a PWM signal), the pulse width modulation signal
being configured to control the state of the backlight source; and
step S104, determining the state of the backlight source based on
the pulse width modulation signal.
For example, when the pulse width modulation signal is a high-level
signal, it can be determined that the backlight source is in the on
state; and when the pulse width modulation signal is a low-level
signal, it can be determined that the backlight source is in the
off state. However, the present disclosure is not limited thereto.
For example, when the pulse width modulation signal is the
low-level signal, it can be determined that the backlight source is
in the on state; and when the pulse width modulation signal is the
high-level signal, it can be determined that the backlight source
is in the off state, which depends on a specific situation.
It shall be noted that the present disclosure is not limited to
determining the state of the backlight source by acquiring the
pulse width modulation signal. In an embodiment, the state of the
backlight source may be determined by directly detecting brightness
of the backlight source, which may specifically include: step S112,
detecting the brightness of the backlight source; step S114,
determining that the backlight source is in the on state when the
brightness of the backlight source is greater than a preset
threshold; and step S116, determining that the backlight source is
in the off state when the brightness of the backlight source is
less than or equal to the preset threshold.
It should be understood that this preset threshold may be set
according to specific situations.
A duration of a gate drive signal corresponding to the sub-pixel is
a sum of the charging time of the sub-pixel and a gate output
enable time (i.e., GOE time) corresponding to the sub-pixel. The
GOE time is a time taken for the gate drive signal to shift from a
high-level to a low-level or the time taken for the gate drive
signal to shift from the low-level to the high-level. The pixel
cannot be charged within the GOE time.
Since the duration of the gate drive signal corresponding to the
sub-pixel is determined, in order to adjust the charging time of
the sub-pixel, the GOE time corresponding to the sub-pixel can be
adjusted. That is, in an embodiment, the adjusting a charging time
of a sub-pixel corresponding to the backlight source according to
the state of the backlight source may specifically include: step
S202, adjusting the gate output enable time corresponding to the
sub-pixel corresponding to the backlight source according to the
state of the backlight source; and step S204, calculating the
charging time corresponding to the gate output enable time based on
a preset correspondence between the gate output enable time and the
charging time.
When the backlight source is in the on state, the gate output
enable time corresponding to the sub-pixel corresponding to the
backlight source is a first gate output enable time. When the
backlight source is in the off state, the gate output enable time
corresponding to the sub-pixel corresponding to the backlight
source is a second gate output enable time. The second gate output
enable time is greater than the first gate output enable time.
It should be noted that the preset correspondence between the gate
output enable time and the charging time described above is that
the sum of the gate output enable time and the charging time is
equal to the duration of the gate drive signal.
For example, when designing a product, an optimal GOE time
(assuming A) is set according to a simulation experiment, the GOE
time is controlled according to the backlight state by setting a
gain coefficient value (assuming B), and then the charging rate of
sub-pixel is controlled. Specifically, when the backlight state is
in the off state, the charging rate of the sub-pixel is good. At
this time, the actual GOE time T1 corresponding to the sub-pixel
may be A.times.B.times.C1, and the C1 may be 100%; when the state
of the backlight source is in the on state, the charging rate of
the sub-pixel is poor, that is, it is lower than the charging rate
when the backlight source is in the off state. Therefore, in order
to increase the charging rate of the sub-pixel when the backlight
source is in the on state to be the same as the charging rate when
the backlight source is in the off state, the GOE time may be
shortened. That is, at this time, the actual GOE time T2
corresponding to the sub-pixel may be A.times.B.times.C2, and the
C2 is less than C1, for example, the C2 may be 90%, 80%, 70% and so
on. It should be noted that the value of C2 may be determined by
measuring the brightness of different products, and be controlled
separately according to the different products.
Based on the pixel charging method described in the foregoing
embodiments, an embodiment of the present disclosure further
provides a pixel charging circuit 30.
As shown in FIG. 3, the pixel charging circuit 30 includes: a
signal acquiring circuit 302, configured to acquire a state of a
backlight source; and an adjusting circuit 304, coupled to the
signal acquiring circuit 302 and configured to adjust a charging
time of a sub-pixel corresponding to the backlight source according
to the state of the backlight source.
The adjusting circuit 304 is configured to adjust the charging time
of the sub-pixel corresponding to the backlight source to be a
first charging time when the backlight source is in an on
state.
The adjusting circuit 304 is configured to adjust the charging time
of the sub-pixel corresponding to the backlight source to be a
second charging time when the backlight source is in an off state,
and the second charging time is shorter than the first charging
time.
In an embodiment, the signal acquiring circuit 302 may include: a
signal acquiring sub-circuit, coupled to a pulse width modulation
circuit and configured to acquire a pulse width modulation signal
generated by the pulse width modulation circuit, wherein the pulse
width modulation signal is configured to control the state of the
backlight source; and a first determining sub-circuit, coupled to
the signal acquiring sub-circuit, and configured to determine the
state of the backlight source based on the pulse width modulation
signal.
For example, the first determining sub-circuit is configured to
determine that the backlight source is in the on state when the
pulse width modulation signal is a high-level signal; and determine
that the backlight source is in the off state when the pulse width
modulation signal is a low-level signal. However, the present
disclosure is not limited thereto. The first determining
sub-circuit may also be configured to determine that the backlight
source is in the on state when the pulse width modulation signal is
the low-level signal; and determine that the backlight source is in
the off state when the pulse width modulation signal is the
high-level signal, which depends on the specific situation.
In another embodiment, the signal acquiring circuit 302 may
include: a brightness detecting sub-circuit, configured to detect
brightness of the backlight source; and a second determining
sub-circuit, configured to determine that the backlight source is
in the on state when the brightness of the backlight source is
greater than a preset threshold, and determine that the backlight
source is in the off state when the brightness of the backlight
source is less than or equal to the preset threshold.
In an embodiment, the adjusting circuit 304 may include: an
adjusting sub-circuit, coupled to the signal acquiring circuit 302
and configured to adjust a gate output enable time corresponding to
the sub-pixel corresponding to the backlight source according to
the state of the backlight source; and a calculating sub-circuit,
coupled to the adjusting sub-circuit and configured to calculate
the charging time corresponding to the gate output enable time
based on a preset correspondence between the gate output enable
time and the charging time.
The adjusting sub-circuit is configured to adjust the gate output
enable time corresponding to the sub-pixel corresponding to the
backlight source to be a first gate output enable time when the
backlight source is in the on state.
The adjusting sub-circuit is configured to adjust the gate output
enable time corresponding to the sub-pixel corresponding to the
backlight source to be a second gate output enable time when the
backlight source is in the off state, and the second gate output
enable time is longer than the first gate output enable time.
For example, as shown in FIG. 4, the pixel charging circuit 30
described in the embodiment of the present disclosure may be part
of a timing controller 3, and the aforementioned pulse width
modulation circuit 31 may also be part of the timing controller
3.
Specifically, the pixel charging circuit 30 in the timing
controller 3 may be coupled to the pulse width modulation circuit
31, and the pulse width modulation circuit 31 may also be coupled
to a driver 4 of an LED backlight source. The pulse width
modulation circuit 31 may control an on/off state of the LED
backlight source by controlling the driver 4. While the pulse width
modulation circuit 31 controls the on/off state of the LED
backlight source, the pixel charging circuit 30 may obtain a
modulation signal generated by the pulse width modulation circuit
31, and according to the modulation signal, automatically adjust a
GOE time, thereby adjusting the pixel charging rate, so that a
display product has uniform brightness under different backlight
frequencies, which avoids incontinuity of the frame, and thus
improves uniformity of the frame.
The present disclosure further provides a display control method
for a display device. The display device may include a plurality of
pixel display areas, and each pixel display area includes at least
one row of sub-pixels. The display control method may include: step
S50, acquiring a state of a backlight source corresponding to each
of the pixel display areas; and step S60, adjusting a charging time
of a sub-pixel corresponding to the backlight source according to
the state of the backlight source.
When the backlight source is in an on state, the charging time of
the sub-pixel corresponding to the backlight source is a first
charging time.
When the backlight source is in an off state, the charging time of
the sub-pixel corresponding to the backlight source is a second
charging time, and the second charging time is shorter than the
first charging time.
The specific acquring method of step S50 may refer to the specific
acquring method of step S10, and the specific adjusting method of
step S60 may refer to the specific adjusting method of step S20,
which is not described again in this embodiment.
It should be noted that a plurality of backlight sources may be
provided correspondingly in each pixel display area. The states of
the plurality of backlight sources in each pixel display area shall
be consistent, and the states of backlight sources in different
pixel display areas are adapted to be changed periodically.
For example, as shown in FIG. 5, whithin one frame time, the
backlight has 3 cycles, and 2160 rows of sub-pixels (excluding
blanking areas) of a display panel are scanned. According to the
backlight cycle, the 2160 rows of sub-pixels is divided into 6
pixel display areas, that is, each of pixel display area includes
360 rows of sub-pixels and corresponds to a periodic on or off
state of the backlight source. An GOE time corresponding to the
sub-pixel corresponding to the backlight source in the on state
(corresponding to ON in FIG. 5) shall be shorter than the GOE time
corresponding to the sub-pixel corresponding to the backlight
source in the off state (corresponding to OFF in FIG. 5), so that
the charging rate of the sub-pixel corresponding to different
states of the backlight source is substantially the same, that is,
the brightness thereof is substantially the same, which can prevent
bright and dark stripes from exhibiting on one frame and avoid
incontinuity of the frame, and then can ensure the uniformity of
the frame, thereby improving the display effect.
The present disclosure also provides a display device having a
display area and a non-display area. The display area includes a
plurality of sub-pixels arranged in an array, and the non-display
area includes the pixel charging circuit described in any of the
foregoing embodiments. The pixel charging circuit is coupled to the
sub-pixel.
In addition, the display device may further include a backlight
module. The backlight module includes a plurality of backlight
sources, and the backlight sources may correspond to the
sub-pixels.
According to the embodiment of the present disclosure, the specific
type of the display device is not particularly limited, and the
display device may be of any type commonly used in the art, for
example, may be a liquid crystal display device such as
televisions, computers, mobile phones, watches, etc. The specific
type may be selected correspondingly by those skilled in the art
according to a specific application of the display device, which is
not repeated herein.
The terms "a", "an", "the" and "said" are used to indicate the
presence of one or more elements/components/etc.; the terms
"include" and "having" are used to include open-ended inclusive
meaning and means that there may be additional
elements/components/etc. in addition to the listed
elements/components/etc.; the terms "first", "second", etc. are
only used as markers, and are not used to limit the number of their
objects.
Those skilled in the art will readily contemplate other embodiments
of the present disclosure after considering the specification and
practicing the invention disclosed herein. This disclosure is
intended to cover any variations, uses, or adaptations of this
disclosure. These variations, uses, or adaptations follow the
general principles of this disclosure and include common general
knowledge or conventional technical means in the technical field
not disclosed in this disclosure. It is intended that the
specification and examples are considered as exemplary only, with a
true scope and spirit of the disclosure being indicated by the
following claims.
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